ECF is caused by protozoa Theileria parva. They are obligate intracellular parasites that infect the host’s lyphoblasts.
East Coast Fever is spread in sub-Saharan Africa.
The fatality rate for untreated ECF can be as high as 100% in cattle from non–endemic areas. In contrast, the morbidity rate is 100% among indigenous cattle, but the mortality rate is usually low. There are about 50 million cattle at risk (with 10 million calves per annum) and the total yearly cost of the disease is estimated to be US $596 million.
ECF is transmitted by ticks, acting as biological vectors. Theileria sporozoites are transmitted to animals through saliva of the feeding tick. Transmission can also occur via reused needles. Animals that have survived the infection tend to be carriers.
The incubation period for ECF is eight to 12 days. Pathology includes fever, enlarged lymph nodes, anorexia, laboured breathing, corneal opacity, nasal discharge, diarrhoea and anaemia. Infected cells sometimes block capillaries in the central nervous system and cause neurological signs.
In endemic areas, the tick numbers can be controlled with acaricides and other methods of tick control such as rotational grazing. Antiparasitic drugs are effective in animals with clinical signs. Vaccination against ECF is done by simultaneously injecting virulent T. parva and an antibiotic (usually a long-acting tetracycline).
For further information, view our ECF product development work.